Photographic systems comprising silver halide particles with occluded metal ions therein,a halogen acceptor,and an organic aldehyde



nited States Patent M 3,547,647 PHOTOGRAPHIC SYSTEMS COMPRISING SILVER HALIDE PARTICLES WITH OCCLUDED METAL IONS THEREIN, A HALOGEN ACCEPTOR, AND AN ORGANIC ALDEHYDE Robert E. Bacon, Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed Oct. 2, 1967, Ser. No. 671,988

Int. Cl. G03c 1/28 US. Cl. 96-94 16 Claims ABSTRACT OF THE DISCLOSURE Photographic print-out compositions comprising: (1) silver halide formed in the presence of trivalent or tetravalent metal ions (2) a halogen acceptor and an organic aldehyde.

Ihis invention relates to radiation-sensitive silver halide materials. In one aspect this invention relates to a printout silver halide emulsion containing silver halide grains with occluded trivalent or tetravalent ions therein and having a halogen acceptor and an organic aldehyde in said emulsion. In still another aspect this invention relates to a print-out emulsion with improved incubation stability, increased maximum density, and increased speed when said emulsions are heated before photodevelopment to provide stabilized print-out materials.

Emulsions which have good print-out characteristics are generally known in the art. In one instance, emulsions of this type generally contain silver halide grains which have been precipitated in the presence of trivalent or tetravalent metal ions in an acidic medium. French Pat. 1,456,581 made available Oct. 28, 1966, discloses several emulsions of this type. However, it is desirable to improve the photographic properties and physical images obtained in emulsions of this type.

In some instances, print-out emulsions of the type disclosed in French Pat. 1,456,581, can be utilized in a process which includes heat treatment of the emulsion before photo-development to obtain a direct-print type image such as the process disclosed in French Pat. 1,490,- 026 issued June 19, 1967. It is also desirable to improve the physical and photographic properties of the emulsions used in this process.

Therefore it is an object of this invention to provide new radiation sensitive emulsions.

It is another object of this invention to provide new radiation-sensitive emulsions which can be used to prepare visible images directly by exposure to light.

It is another object of this invention to provide novel radiation sensitive emulsions with improved incubation and long term keeping stability.

It is another object of this invention to provide novel radiation sensitive emulsions which will provide images with increased D and decreased D It is still another object of this invention to provide novel silver halide systems that can be used in a photodevelopment process.

It is a further object of this invention to provide emulsions which have increased speed when heated before photodevelopment to provide stabilized print-out materials.

These and other objects of the invention are accomplished with a radiation-sensitive silver system containing 1) silver halide grains formed in the presence of trivalent or tetravalent metal ions (2) a halogen acceptor and (3) an organic aldehyde. In another aspect of the invention nitrogen containing halogen acceptors and preferably urazole type halogen acceptors are used in the emulsion. In

3,547,647 Patented Dec. 15, 1970 another aspect, non-halogenated, low molecular weight aldehydes such as formaldehyde, gluteraldehyde, or crotonaldehyde are used in the emulsion. In still another aspect, the emulsions which contain aldehydes according to this invention exhibit increased. D decreased D good incubation stability and high speed when briefly imagewise exposed to light or other radiation, heated and then photodeveloped. The improvements in physical and photographic properties of the emulsions of this invention containing both urazole type halogen acceptors and aldehydes such as formaldehyde is quite unexpected as the prior art is replete with suggestions that adverse effects are obtained when aldehydes and urazoles are used in conventional developing-out emulsions.

The silver halide compositions which are generally useful in accordance with this invention comprise silver halide grains having trivalent or tetravalent metal ions or atoms occluded therein. The silver halide grains having occluded trivalent or tetravalent metal ions therein are generally obtained by precipitating in the presence of the trivalent or tetravalent metal ions. Typical emulsions of this type are disclosed in French Pat. 1,456,581, made available Oct. 28, 1966, and in Bacon U.S. Ser. No. 629,090 filed Apr. 7, 1967.

The silver halide compositions of this invention have a halogen acceptor therein Which is generally contiguous with the silver halide grains in the system. Generally the halogen acceptors are nitrogen containing halogen acceptors such as those disclosed in Bacon et al., French Pat. 1,4565 81, and preferably they are urazole type halogen acceptors such as disclosed in Bacon et al., French Pat. 1,450,984, issued Aug. 18, 1966. Typical urazole type halogen acceptors include urazole sodium salt, urazole, 3-thiourazole, 3,5-dithiourazole, 3l,5-dithiourazole hydrazine salt, 4-aminourazole hydrazine salt, 4--(1-naphthyl)- urazole, 4-ethyl urazole, l-phenyl urazole, 4-phenyl urazole, l-butyl urazole, l-octyl urazole, 4-butyl-3,5-dithiourazole, 1,4-diphenyl urazole, 1,4-dibutyl urazole, 1,4-dibutyl-3,5-dithiourazole, 1,4-diphenyl-3,5-dithiourazole, 1- ethyl-4-phenylurazole, 1-ethyl-4-phenyl-3,5-dithiourazole, 3-thio-5-iminourazole, 3,5-diselenourazole and the like.

The silver halide system contains an organic aldehyde in combination with the halogen acceptor in the composition. Generally, most non-halogenated, organic aldehydes or aldehyde precursors which form non-halogenated organic aldehydes can be utilized in the emulsions of this invention to improve physical and pohtographic properties of the system. Typical useful aldehydes include formaldehyde, gluteraldehyde, crotonaldehyde, glyoxal succinaldehyde fumaric dialdehyde zacetaldehyde benzaldehyde terephthaldehyde and the like. Typical aldehyde precursors are paraformaldehyde sodium formaldehyde bisulfite and paraldehyde. Preferably the organic aldehyde has a molecular Weight of less than about 200 and contains no more than 2 oxygen atoms.

Various colloids can be used as vehicles or binding agents in preparing the silver halide emulsions of this invention. Satisfactory colloids which can be used for this purpose include any of the hydrophilic colloids generally employed in the photographic field, including, for example, gelatin, colloidal albumin, polysaccharides, cellulose derivatives, synthetic resins such as polyvinyl compounds, including polyvinyl alcohol derivatives, acrylamide polymers and the like. In addition to the hydrophilic colloids, the vehicle or binding agent can contain hydrophobic colloids such as dispersed polymerized vinyl compounds, particularly those which increase the dimensional stability of photographic materials. Suitable compounds of this type include water-insoluble polymers of alkyl acrylates or methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates and the like.

The above-described emulsions of the invention can be coated on a wide variety of supports in accordance with usual practice. Typical supports for photographic elements of the invention include, glass, metals, paper, polyethylene-coated paper, polypropylene-coated paper, cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethyleneterephthalate film and related films of resinous materials and others.

The present silver halide system can also be utilized as light-developable materials, particularly those composed of fine-grain silver halide having an average grain size of less than about .2 micron and typically about .01 to .2 micron, and particularly those silver halide grains formed in the presence of bismuth ions. A suitable lightdevelopment process is described in Colt French Pat. 1,490,026 issued June 19, 1967. In such a photodevelopment application, the silver halide coating is imagewise exposed to form a latent image, the exposed coating heated to at least about 300 F., and after heating the coating is uniformly exposed to light for a time sufficient to produce a visible image. The heating step in such a photodevelopment process represses the usual printing out of unexposed or non-image areas (D the original recording sensitivity of the silver halide being inactivated by such heating. Direct-print images thus prepared have a high degree of permanence or stability to ambient light. The emulsions of this invention which are used according to this process exhibit reduced D increased D increased speed and greatly improved incubation stability.

The present silver halide systems can be effectively utilized to provide immediate paper prints or transparencies which can be projected on a screen. In this latter embodiment the silver halide emulsions are coated on a transparent support having good dimensional stability at temperatures above 300 F. The resulting element can be processed according to the process of Colt, French Pat. 1,490,026 isued June 19, 1967, to provide a good print or transparency.

The transparency can be formed by heating the photographic element to temperatures of above 300 F. by the process generally disclosed in Colt. Good results are obtained in this process when the film support of the photographic element has a heat distortion temperature of at least 160 C. in both the length and width directions of said support; heat distortion temperatures are calculated according to ASTMDl637-61. In the preferred embodiments superior results are obtained when a transparent film support is used which has a heat distortion temperature of at least 180 C. in both the length and width directions. Typical supports which can be used are the heat set polyesters, for example polyethyleneterephthalates, cyclohexylenedimethyleneterephthalates, for example, as disclosed in Kibler et al., US. Pat. 2,901,466, issued Aug. 25, 1959, and the like; high temperature polycarbonates, for example, polycarbonates such as disclosed in copending application Ser. No. 292,139 by Caldwell and Jackson filed July 1, 1963, and the like; high temperature polyimides, for example, those disclosed in Chemical and Engineering News, Aug. 24, 1964, pp. 24-25, and the like. In particular, typical high temperature commercial supports useful in construction of the element are Kodak T-16 polyester, Kodak K-1 polycarbonate, Du Pont Kapton Type H polyimide, Kodak Estar polyester and the like.

The invention can be further illustrated by the follow ing examples, although it will be understood that the examples are included merely for purposes of illustration and are not intended to limit the scope of the invention unless otherwise indicated.

EXAMPLE 1 A radiation-sensitive gelatino silver chlorobromide (5 mole percent chloride and 95 mole percent bromide) photographic emulsion having an average grain size of .08 micron is prepared by slowly adding simultaneously an aqueous solution of silver nitrate and an aqueous solution of alkali metal halides to an agitated aqueous gelatin solution containing 75 mg. of bismuth nitrate pentahydrate per silver mole at 30 C., at a pH of about 2.0 adjusted with nitric acid.

The emulsion is divided into two portions to which are added the halogen acceptors respectively:

(1) dithiourazole (16 gm./ Ag mole) (2) dithiourazole hydrazine salt (20 gram/Ag mole) One part of each respective emulsion serves as a control and to additional parts formaldehyde is added at the concentrations in the table below. The respective emulsions are then coated on formaldehyde-free paper support and dried.

Two sets of these coating are printed out 5 minutes at 6 inches from two 8-watt BL fluorescent lamps in a white reflector. Maximum densities are recorded fresh, and after seven days incubation at 120 F./ 35 RH.

Print-out, D

Halogen Formaldehyde, grit/Ag mole acceptor Fresh Incubated Control (l) 82 81 94 The increased fresh D and the stabilizing efiect of formaldehyde is evident from the above data.

Similar results are obtained when the trivalent rhodium and iridium salts are used in the place of bismuth salts and when tetravalent platinum and osmium salts are used in place of bismuth. Similar results are also obtained when urazole and thiosemicarbazide are used as halogen acceptors.

EXAMPLE 2 Similar emulsions are prepared according to Example 1 with the halogen acceptors as set forth in Example 1. Portions of the respective emulsions served as control samples and to other portions is added gluteraldehyde in the concentrations set forth in the following table. The respective emulsions are coated on formaldehyde-free paper, dried and tested in accordanre with Example 1.

Print-out Dmx Halogen Gluteraldehyde, gin/Ag mole acceptor Fresh Incubated Control (2) 1. 00 54 (5) (2) 1. 05 96 (15) (2) 1.05 97 EXAMPLE 3 Relative Formaldehyde speed Dmax Dmln AD Absent 100 1. 32 5s 74 Present 191 1. 45 42 1. 03

The addition of formaldehyde improves the photographic characteristics of the material by increasing speed, lowering D and increasing D Similar results are obtained when gluteraldehyde, crotonaldehyde, benzaldehyde, glyoxal, succinaldehyde, fumaric dialdehyde, crotonaldehyde, acetaldehyde, and terephthaldehyde and the aldehyde precursors paraformaldehyde, sodium formaldehyde bisulfite and paraldehyde are used in the silver halide system above.

EXAMPLE 4 Silver bromoiodide emulsion is prepared as described in Example 1 using the appropriate alkali metal halides and dithiourazole hydrazine salt is added to the emulsion at a concentration of 20 gm./Ag mole. Formaldehyde is added to separate portions of the emulsion at the concentrations of the table below.

Samples of the respective emulsions are processed by exposing 1 second on a Kodak Regent Printer through a 0.15 AD step wedge, heating at 235 C. for 5 seconds on a hot platen and photodeveloping 5 minutes at 6 inches from two 8-watt BL fluorescent lamps in a white refiector.

Maximum and minimum densities and the number of visible steps are recorded fresh and after 7 days incubation at 120 F./35% RH.

Fresh test Incubated No. of .15 AD steps Formaldehyde g mole) max m in m ax D... in Fresh Ineubated EXAMPLE 5 Photographic emulsions are prepared and tested in accordance with Example 4 except that gluteraldehyde is used in place of formaldehyde.

Fresh test Incubated No. of .15 AD steps Gluteraldehyde -I E 111016) Dmx min Dmn! Dmin Fresh Ineubated Although the invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove, and as defined in the appended claims.

I claim:

1. A print-out silver halide composition containing silver halide grains having trivalent or tetravalent metal ions occluded therein, said composition comprising an organic aldehyde and a halogen acceptor.

2. A print-out composition as described in claim 1 wherein said silver halide grains are formed in the presence of said trivalent or tetravalent metal ions.

3. A print-out composition according to claim 2 wherein said metal ions are in the form of trivalent metal ion salts.

4. A print-out composition according to claim 2 wherein said metal ions are in the form of tetravalent metal ion salts. V

5. A print-out composition according to claim 1 wherein said halogen acceptor is a nitrogen containing halogen acceptor.

6. A print-out composition according to claim 1 wherein said halogen acceptor is a urazole type halogen acceptor.

7. A print-out composition according to claim 1 wherein said halogen acceptor is a dithiourazole.

8. A print-out composition according to claim 1 Wherein said aldehyde has a molecular weight less than 200 and contains no more than 2 oxygen atoms.

9. A print-out composition according to claim 1 wherein said aldehyde is formaldehyde.

10. A print-out composition according to claim 1 wherein said aldehyde is gluteraldehyde.

11. A print-out composition according to claim 1 wherein said silver halide is at least 50 molar percent bromide.

12 A radiation sensitive silver halide system comprising silver halide grains having trivalent metal ions occluded therein, a urazole type halogen acceptor, and an organic aldehyde.

13. A radiation sensitve silver halide system according to claim 12 wherein said trivalent metal ion is bismuth.

14. A radiation sensitive silver halide system according to claim 12 wherein said trivalent metal ion is iridium.

15, A radiation sensitive system according to claim 12 wherein said halogen acceptor is dithiourazole hydrazine salt.

16. A radiation sensitive system according to claim 12 wherein said aldehyde is formaldehyde.

References Cited UNITED STATES PATENTS 2,588,982 3/1952 Ives 9664 3,457,072 7/ 1969 Ditzer ct a1. 9627 3,458,317 7/1969 Ditzer et a]. 9694 NORMAN G. TORCHIN, Primary Eraminer .J. R. HIGHTOWER, Assistant Examiner U.S.". Cl. X.R. 96108 

